refactor(cli): restrict DENO_UNSTABLE_CONTROL_SOCK to local transports (#35276)
The unstable control socket (`DENO_UNSTABLE_CONTROL_SOCK`) accepted a
`tcp:` address in addition to `unix:` and `vsock:`. The control socket is an
orchestration primitive meant for local, single-host coordination
between a supervisor and the Deno process it manages, so a network-facing TCP
listener isn't a transport it should expose.
This drops the `tcp:` arm in `wait_for_start` (and the now-unused
`TcpListener` import). A `tcp:` address now falls through to the
existing "invalid control sock" error rather than binding a TCP port. The `unix:`
and `vsock:` transports are unchanged, and all existing control-socket specs
use `unix:`, so nothing in the test suite relies on the removed form.